Technology of drilling wells for water. Types of water wells

In many regions, when it is impossible to connect to centralized water supply, water wells are drilled from underground horizons. Isolated from surface sources of contamination by strata of rocks, underground waters, as a rule, meet the sanitary standards established for domestic water. With additional cleaning, passing through the filtering device, they acquire a high quality of drinking water.

What you need to know

The determining criteria for choosing a method of drilling a water intake well are the depth of the groundwater level and the rocks of the geological section that are to be excavated. Correctly chosen technology of water well drilling will allow to drill a well quickly, to avoid emergency situations during drilling. As a result, this will make it possible to get the highest rate of water intake in the given conditions .

What does the technology of drilling wells under water mean? This is the way and mode of destruction of various rocks, cleaning the wellbore and fixing its walls, equipment of the water intake part.

Methods of drilling

Rotary and impact-cable drilling is usually used to build deep water wells. The technology of drilling water wells in these ways is different. Features of each do not allow to apply them without restrictions in any conditions. The technology of drilling water wells with a drilling rig with the rotation of a rock cutting tool (bit) in this article is given in the example of auger and rotor methods.

Screw Drilling Technology

In sandy and clayey rocks that do not contain large inclusions, drilling with a set of bits and screws transporting the drilled rock from the face to the top is used. Of the two types of auger drilling for the installation of a water intake well in a region with a well-studied geological structure, a continuous slaughter is used more often by continuous voyage, by way of trips and by screwing. Wherever it is necessary to obtain high-quality information on the rocks and the depths of their occurrence, the method of the ring face is used.

Continuous Flight (in-line drilling) - the drilled rock is carried out by a screw column on the day surface. As the deepening of the drilling rig is increased by additional augers. They are used for the penetration of homogeneous sands without interlayers of silt or other weak rocks. The rotational speed of the screws is 250-300 rpm. It is impermissible to unnecessarily dive to avoid overfilling the rock blades and jamming the projectile in the well for this reason. Sufficient load is the weight of the screws and the weight of the rotator.

In plastic and hard plastic clayey rocks, voyages are used - the chisel and auger column are drilled into the rock with the subsequent extraction for cleaning the flange from the drilled mass. The value of a voyage within 1 meter. The speed of rotation is from 100 and not more than 300 rpm. Load 500 N.

In weak rocks a spiral bit is used on a screw column - they are screwed to a certain depth and then extracted without rotation by a winch.

The annular slaughter is carried out by special screw augers, which make it possible to extract the core (a column of drilled rock) without lifting the drill string to the surface. The drilling mode is 60-250 rpm, the voyage is from 0.4 to 2.0 m. This technology of drilling water wells is rarely used, mostly by geological organizations engaged in exploration and, in the process, drilling water wells.

Rotary-rotary drilling technology

This method achieves a high rate of penetration and large outcrops of pipe columns. The disadvantages include the clamation (claying) of the aquifer, the large costs of preparing a clay solution, large amounts of water to flush the well to restore the yield of the horizon, clogged up during drilling.

More often used rotary with direct washing: the destroyed rock from the face is brought to the surface by a clay solution pumped into the well by a pump through the drill rods. It is necessary to maintain the rates of the ascending flow in the interval 0.5 - 0.75 m / sec. Circulation of the washing solution is disturbed in strongly fissured zones - it, together with the mud, goes into cracks. The driller needs to carefully look at the drilling mode, reduce the axial load if necessary and smoothly apply washing to avoid stucking the projectile.

Do not need to pursue a high mechanical speed, achieved by increasing the number of revolutions: this is fraught with accidents. The load on the bit and the rotational speed are adjusted depending on the passable rocks, bit diameter and drill pipes, the amount of washing liquid.

Turnovers should be reduced when:

• Bit parameter increases;
• Reducing the diameter of the drill string;
• Increase in rock strength;
• When alternating layers with low power (up to 1.5 m).

On rotary installations such as URB and BA, they work mainly at II-III speeds. The passage of clayey and argillaceous-sandy rocks is carried out at 300-400 rpm (III-IV speed). For rocks of moderate strength (sandstones, limestones, marls), the rotor rotation range is from 200 to 300 rpm. Strong rocks are drilled with a bit with a rotation speed of 100-200 rpm.

The driller closely follows the drilling mode, reducing the axial load and smoothly flushing to avoid picking up the projectile. The moment the aquifer is opened reveals a sudden drop in the clay solution and an increase in the load on the engine. The circulation of the solution is disturbed in highly fractured zones - the cuttings and the solution go into cracks.

If the aquifers are indigenous with small cracks, the opening of the horizon is carried out with a qualitative clay solution with a mandatory outlet to the surface.

The technology of drilling water wells with a small drilling rig is similar to the technology of drilling with powerful machines.

Related work

Fastening of walls of a chink by pipes is spent after drilling. Apply metal, asbestos-cement and plastic pipes. The type of filter (perforated or mesh) is selected depending on the water-bearing rocks.

Before installing the filter, the solution is replaced with a lighter one, the specific gravity is not more than 1.15. After installing the filter, immediately flush the well with water. Then, the well is bored - pumping a column of liquid out of the borehole with a bailer. When clarification of the washing and appearance of sand in it begin pumping airlift. With the termination of sand removal and full clarification of water, a submersible pump is installed.

Energy of a free falling blow

The low-power water-bearing horizons (less than 1 m) are opened with a shock-rope method without problems. It is possible to obtain the maximum production rate - the water-bearing rocks are not clogged. Do not need a long pumping.

The method is used:

• In poorly studied terrain;
• In waterless areas where water delivery is impossible to prepare a solution;
• If it is necessary to separately test several horizons;
• For wells with a large initial diameter.

Disadvantages of rock-cable drilling:

• Small speed of penetration;
• Large pipe consumption for casing;
• Limited depth of drilling (up to 150 m).

The normal frequency of strokes of the free-falling projectile is calculated. It is inversely proportional to the square root of the drop height: with increasing the height of the bit above the face, the frequency of impacts is reduced and, conversely, the number of strokes increases with decreasing height.

Need power and savvy

With a shallow groundwater table (usually groundwater) and a geological section folded by loose rocks, the well can be drilled in the cramped conditions of the built-up area, using the muscular strength of people - 2 people are enough.

The technology of drilling water wells manually is simple. It is possible to apply a driving method or screw.

For driving a steel pipe 1 inch in diameter , it is preliminarily cut into 2 or 3 meter lengths. At the ends make an external thread. As the sections become deeper, the pipes will be joined by couplings with internal threads. A special steel tip (shank) is made in the form of a cone, the diameter of the base is 1 cm larger than the diameter of the pipe. It is welded to the pipe. About a meter of the length of the pipe above the tip (enough 60 cm) is allocated to a primitive filter - a water-receiving device for penetrating the well from the aquifer into the well. A drill of 6 mm is made holes 5 cm apart.

The chopper is placed on the pipe from two separate parts. The first is an emphasis with a cone hole under the pipe. Its outlet is larger than the outside diameter of the hammered pipe by 5 mm, which is enough to insert two wedges in the gap from below - a metal truncated cone cut across the length. The diameter of the tip of the cone is slightly larger than the diameter of the tube, but less than the outlet opening of the stop. The second part is a shock "woman," a cargo with a through hole for the pipe and two handles for lifting above the stop.

When the woman is lowered at the moment of impact of her against the emphasis, the wedges enter the hole and hold the clogged pipe in their "arms." After driving a piece of pipe, the cone is knocked out, the pipe is built up, screwed up with the following piece. Rearrange the stop with wedges, put on the "babu" and continue to clog the pipe to the aquifer. Periodically, you need to rotate the pipe around the axis.

The appearance of water in the well is determined by lowering the inside of its weight, tied to the string. If it is lifted up wet, then the well is deepened into the aquifer. It is important not to "slip through" this layer that gives water. It is necessary to leave the perforated end of the pipe in this water-saturated rock. And proceed to pump the minivan first hand pump. As the clarification of the water goes to pumping a surface water pump.

Screw hand drilling of water wells - the technology is similar to that described with the help of a drilling rig, which is replaced by two people. Of course, they can not keep up with the parameters of the mechanical drilling regime. Some craftsmen replace physical force with mechanisms.

Drilling of water wells

The technology is simple with minimal costs of materials, strength and time. Conditions - the depth of the well is up to 10 m, the section is composed of loose soils.

Equipment - pump "Baby", capacity under the water (the larger the volume, the better, but it is possible and a barrel of liters for 200). The gate for turning the pipe is made of two tubes and a clamp.

Materials: pipe diameter 120 mm, length to the depth of the well. At the bottom end, the teeth are cut, the upper end is equipped with a flange with a union through which water from the barrel under the pressure created by the pump "Baby" will flow through the hose. To fix the flange to the edge of the pipe, 4 lugs with holes for M10 bolts are welded.

Labor: it is easier to work together. The cost of time is 6 meters per day on loam 1-2 hours.

The drilling process: dig a pit about a meter deep, install a pipe vertically in it and pump water into it. Water, going through the lower end with incisors, will blur the ground, freeing up space under the pipe, which will settle under its own weight. It is only necessary, shaking, to turn the pipe in order for the teeth to crumble the rock. Drilled particles of the rock under pressure come out together with water in the pit. From it, you can scoop out water and, after filtering, re-use it for washing. After reaching the aquifer, remove the flange, and into the well under the water level, but before reaching the bottom, the pump is pumped for evacuation.

Types of water wells

They are divided into unfiltered and filter. Filtration wells are arranged in aquifers, composed of fine-grained sands or in stable fractured rock. For other aquifers, a filter is selected depending on the fractions of the water-bearing rocks.